Many different products have utilized, and continue to utilize, sheet metal as a raw material for constructing various components. Sheet metal generally possesses a high tensile strength, but is often very flexible. For structural purposes, the flexibility can be reduced through the use of additional structure attached to the sheet metal, such as beams, purlins, bars, and posts, among others. Additional structural components, however, increase the cost for the additional materials and increase the size and weight of the assembled component.
One method for avoiding the requirement for additional structure is to break or bend the sheet along a line where the reduction in flexibility is desired. When done as a series of parallel bends to form channels or ridges, this is known as corrugating. Corrugating is known to produce metal sheet products with significantly reduced flexibility along at least one axis. Although the corrugation may be produced by performing a series of independent breaks on a metal sheet, corrugating machines also referred to as roll forming machines have been developed to provide corrugation to flat sheet metal in a continuous process. An example of the prior art relating to roll forming machines can be found in U.S. Pat. No. 4,269,055, which is hereby incorporated by reference in its entirety.
Metal sheets are often used in applications where specific aesthetic properties are desirable on at least one surface of the metal sheet. In some cases, the aesthetic property may constitute a specific color. Methods for applying a solid color to corrugated metallic products have previously been performed using spraying or coating processes 100, as illustrated in FIG. 1. Referring to FIG. 1, the flat metallic product 110 is unrolled from a coil 102 and made proximate to, for example, spray nozzles 120, which deliver a sprayed paint or coating 130 to the surface of the flat metallic product 110. After coating or painting, the flat metallic product is dried or cured using, for example, a heater or oven 140 and then rolled into a coil 104. Other cases may require specific graphical images or patterns in lieu of a solid color. Some methods of applying a graphical image or pattern to flat metallic product include immersion graphics methods where, for example, an inked film is applied to the flat metallic product, which is then immersed to dissolve the film, leaving the ink image or pattern on the flat metallic product. Like the painted coating products discussed above, the immersion graphics products may not provide a surface that is sufficiently resistant to scratching, abrasion, weathering, or fading due to outdoor exposure or mechanical impact associated with subsequent processing, assembly, or use.
One technique for providing mechanically resilient protection for metallic sheet products includes laminating. The laminating process 200 in this context, as illustrated in FIG. 2, includes adhesively bonding a graphic film 202 to at least one surface of a flat metallic sheet 201. By way of example, the graphic film 202 may be applied using the pressure of a laminating roll 220. Additionally, the laminating roll 220 may possess specific surface properties which are transferred or embossed into the surface of the graphic film 202 during application. The resulting laminated metallic sheet 210 includes a graphic film 202, which may possess specific aesthetic properties including solid colors, metallic finishes, patterns, and graphical images. Additionally, if embossing was performed, the graphic film 202 may possess specific surface finish properties such as brushed, matte, or pebbled, among others. This process, however, has only been applicable to flat products because the manufacturing impracticality of continuously processing laminated corrugated products. For example, previous attempts to corrugate a laminated sheet have resulted in a graphic film that weakens and cracks during subsequent processing and is not resistant to damaging elements associated with an outdoor environment.
Thus, a heretofore-unaddressed need exists in the industry to address the aforementioned deficiencies and inadequacies.